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ENGINBEB DEPARTMENT, U. S. A. 



REPORT 



OF 



EXPERlllEi\'TS WITB THE SEELY A\'D BETHELL PROCESSES 



FOR THE 



PRESERVATION OF TIMBER, 



ACCOMPANIED BY 



DESCRIPTIONS OF THESE PROCESSES 



AND OF THE 



HAYFORD PR(>CESS^f?fc5S^ 



BY 



a. A. GILLMORE, " 

LIEUT. COLONEL OF ENGINEERS, BVT. MAJ. GEX. U. S. A. 



WASHIl^GTOiT: 

GOVEKNMENT PRINTINa OFFICE. 

1879. 






EISTGINEEB DEPARTME^fT, U. S. A. 



REPORT 



OF 



EXPERn!E.\TS WITH THE SEELY AXD BETHELl PROCESSES 



FOR THE 



PRESERVATION OF TDIBER, 



ACCOMPANIED BY 



DESCRIPTIONS OF THESE PROCESSES 



A>T) OF THE 



HAYFORD PROCESS 

S^oF_co»e5 



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WAS\^ 



c.^3: 



Q. A. GILLMORE, 

LIETJT. COLOXEL OF EXGIXEEES, BVT. MAJ. GEX. U. S. A. 



washi]^gto:n"s 

GOYERNMENT PRI^^TINO OFFICE, 
1879. 






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Office of the Chief of Engii^eers, 

Wasliingion D. C, May 23, 1879. 
Sir : I have the lionor to submit liereTvitli a report by Lieut. Col. Q. 
A. G-illinore, of the Corps of Engiueers, of the experiments with the 
Seely and Bethell processes for the i)reservation of timber, which he 
has carried on under the direction of this department, with descrii)tions 
of these processes and of the Hayford process. 

The subject is of importance to the government in connection with its 
military, naval, and civil works, and it is respectfully recommended that 
1,000 copies be printed for the use of the Corps of Engineers and to 
meet the frequent inquiries which are received from other branches of 
the government service and from citizens. 

Very respectfully, your obedient servant, 

H. G. Wrioht, 
Acting Chief of Engineers. 
Hon. Geo. W. McCrary, 

Secretary of War. 

Ax)proved : 

By order of the Secretary of War : 

H. T. Crosby^, 
Chief Cleric. 
War Department, May 28, 1879. 



REPORT 



United States ENaiNEER Office, 

New Yorlcj January 23, 1879. 

General : I have the honor to submit the following report of the 
condition of the wooden platforms for gnns and mortars, in the several 
works of defense under my charge, in response to a request from the 
Acting Chief of Engineers, under date of September 6, 1878. 

Since the year 1870, when wooden platforms for heavy guns and mor- 
tars were first introduced, there have been made for the works under 
my charge, the platforms specified below, viz : 

35 front-pintle platforms for 15'' guns, high traverse. 

23 front-pintle platforms for 15'^ gnns, low traverse. 

1 center-pintle platform for 15^' guns. 

18 platforms for 13'^ seacoast mortars. 

All of these platforms were creosoted, with two exceptions, to wit : 

1 front-pintle platform, first exi)eriment, high traverse. 

1 front-pintle platform, second experiment, low traverse. 

These two platforms have never been creosoted. 

The first, or high-traverse platform, was built at Fort Wadsworth, 
Kew York Harbor, toward the end of the year 1870, and was tested by 
firing in March and April, 1871. The timber of the platform is so much 
decayed as to render it entirely unserviceable. The low-traverse, or 
second exx)erimental platform, was fijiished in Ai3ril, 1873, and soon after 
tested by firing. This platform is not quite so far gone in decay as the 
first one, but still it must be classed as unserAdceable. 

Two methods have been employed in creosoting the platforms, to wit, 
the Seely process and the Bethell process. 

THE SEELY PROCESS. 

This process is ai)plied as follows, viz: 

1. The wood is subjected to a temperature above the boiling-point of 
water and below 300° Fah., while immersed in a bath of creosote oil, 
for a sufficient length of time to expel the moisture. 

2. When the water is thus expelled, and the pores contain only steam, 
the hot oil is quickly replaced by a bath of cold oil, by means of which 
change the steam in the pores of the wood is condensed, and a vacuum 
more or less perfect is formed into which the oil is forced by atmospheric 
pressure and capillary attraction. 



It is claimed for the Seely process that the heating in the hot bath is 
of itself a most thorough, simple, economical, and safe seasoning x)ro- 
cess, the application of the heat being so even and continuous that the 
whole body of the wood is operated on uniformly, and that this season- 
ing is a perfect substitute for any other kind. There is, therefore, no 
necessity for the use of unseasoned wood for the Seely process. 

It is also claimed that the rate of exj)ulsion of the sap, whether total 
or partial, and the amount of oil forced into the wood is under i)erfect 
control of the operator. 

This process is the invention of Prof. 0. A. Seely, of XeAV York, and 
was patented in the United States in September, 1867. 

THE BETHELL PROCESS. 

The Bethell process, as practiced by Messrs. J. G. Moore & Co. at the 
" Central Creosoting Works," at Elizabeth, N. J., is briefly as follows : 

1. The timber is placed in a cylindrical tank, in which, after it has 
been closed so as to be air-tight, a vacuum is formed by a powerful air- 
pump. This draws out the air and the superabundant moisture con- 
tained in the pores of the wood. 

2. The vacuum having been maintained for the requisite time, the tank 
is filled with oil of the temperature of 100^ Fah. A pressure of 150 
pounds per square inch is then employed by the use of a powerful press- 
ure-pump, and continued until the requisite quantity of oil is forced 
into the pores of the wood. 

It is claimed that since in this process the wood is not heated either 
by steam, vapor, fire, or hot bath, the oil being simply warmed to a tem- 
perature but little above that of summer heat, the wood fiber cannot be 
injured by this mode of application, but on the contrary is greatly bene- 
fited and strengthened. 

The Hayford process is claimed to be an improvement on all previous 
methods of treating timber with creosote. Although it had not been 
introduced at the time the platforms were laid, and there is nothing to 
be said from direct experiment and personal knowledge with respect to 
its efficacy in preventing rot, it is thought proper to describe it briefly 
in this connection. 

The process is practiced as follows : 

1. The wood having been placed in the cylindrical tank, steam is ad- 
mitted, which first passes through a coil inside of the cylinder itself. 
The lieat should be increased quite gradually, and be kept moist to keep 
the wood from checking ; atmospheric air is also forced into the cylin- 
der until a i)ressure of 30 to 40 pounds is indicated. A temi)erature 
of 1350° to 270° Fah. is sufficient to evaporate the saj). During the 
steaming process a pipe in the bottom of the cylinder is kept open to 
allow the escape of the liquids and to maintain a current of hot air. In 
this way the albumen is coagulated, and the sap and moisture turned 
into vapor. 



2. The direct steam is cut off, all valves opened, and the air-pumps 
used to drive from the cylinder all the steam, vaporized sap, and liquids, 
heat being maintained through the radiation of the steam-coil. 

3. The cylinder having been made tight again, the air-i)umx)s are now 
applied as exhaust or vacuum pumps, when the vapors, partly con- 
densed in the pump, begin to pour from the nozzle of the pumj) and 
continue so for hours. 

4. Creosote oil heated to the boiling-point is now forced into the cylinder 
under a pressure of about 60 pounds per square inch in the oil-tank, 
which, considering the vacuum in the cylinder, makes a pressure in the 
latter of about 75 pounds. Porous wood like pine absorbs all the oil re- 
quired 5 but with wood of solid and close fiber, and timber of large size, 
a further i)ressure of from 60 to 150 pounds is needed for a certain length 
of time to complete the impregnation. 

It is claimed for this process that nothing liable to ferment remains 
in the wood, which is made entirely water-proof and airtight by injecting 
the pores with creosote oil, and that not only green timber can be 
thoroughly preserved in this manner, but that it is essential to use green 
wood for the puri)ose. 

THE SEELY PROCESS. 

Tiie Seely process has been applied to — 

30 front pintle-platforms for 15^' guns, high tra\'erse. 

1 center-pintle platform for 15^^ guns. 
10 platforms for 13'^ sea-coast mortars. 

These platforms have been laid at the following works : 
5 front-pintle platforms at Glacis gun-battery, ^ew York Harbor. 
10 fi^ont-pintle platforms at Channel Front, Fort Tompkins, l^ew York 
Harbor. / 

4 front-pintle platforms at Battery Hudson, ^ew York Harbor. 

5 front-pintle platforms at Battery Hudson Extension, ]S'ew York 
Harbor. 

10 mortar platforms at Glacis Mortar Battery, 'New York Harbor. 

2 front-pintle platforms at Fort Moultrie, S. C. 
2 front-pintle platforms at Fort Sumter, S. C. 
2 front-pintle platforms at Fort Pulaski, Ga. 

1 center i)intle i)latform at Fort Pulaski, Ga. 

The 5 gun-i^latforms in Battery Hudson Extension, above specified, 
were originally made all wood like the rest, but were subsequently 
modified as follows : 

The radial timbers were cut off a few feet outside the prop-sills, the 
outer ends of the radial timbers and the traverse rail-timbeis were re- 
moved and replaced by stone and concrete work. They are, therefore, 
compound platforms, the inner portion, including pintle-block and prop- 
sills, being of wood, and the outer portion of masonry. 

All the above-named platforms were examined in September, 1878, 



with tlie exception of those at Fort Pulaski, which were examined in 
December, 1878. On Table I are given the results of the examination. 

Of 30 front-pintle ijlatforms examined, all the white-oak portions of 
7 platforms were found sound, while 23 platforms showed each from 
one to nine pieces of oak that were partially or slightly decayed, or 
shaky on the upper surface, with fungi growing out of the cracks, and 
two had the timbers forming the pintle-block considerably decayed. 

In 24 out of 30 front-pintle platforms examined, the yellow pine was 
found quite sound ; four platforms showed each one stick of yellow i^ine 
shaky on the upper surface, while two others (at Fort Moultrie) have 
the tunber forming their i>intle-blocks slightly decayed. 

The center-pintle platform at Fort Pulaski may be said to be in the 
least satisfactory condition of all, since both the oak of which the pintle- 
block consists and the yellow pine that forms the balance of the plat- 
form were found more or less decayed. 

In the case of the ten mortar-platforms at the Staten Island works the 
yellow-pine pieces have remained sound, while many of the oak i)ieces 
that form the top layer are attainted by decay. The front and rear 
pieces of each platform, where in contact with the earth, are rotten from 
one-eighth to one-half inch deep, and at least two-thirds of the pieces gen- 
erally are rotten at the heart from two to four inches diameter, so that 
an iron rod can be run in from 15 to 18 inches deep. In fact, the ai)pear- 
ance and smell of these oak timbers is such as if they had not been 
creosoted at all. 

The difference in the results obtained with creosoted oak and yellow 
pine may consist in the difficulty, or impossibility, of completely dri\'ing 
out the sap from heavy sticks of timber of hard wood, such as oak, and 
that the creosote cannot penetrate to the heart of the timber, but forms 
only a coating of irregular depth. When the summer sun acts on such 
timber it causes it to crack and split, the interior of the timber is no 
longer protected by the coating, and under the influence of alternate 
lieat and moisture, the sap still remaining in the wood begins to ferment 
;and causes the formation of fungi, which rapidly disintegrate and destroy 
the wood. 

Yellow pine being comj)aratively a soft wood, of a much more porous 
texture than white oak, it is possible that when heavy pieces of both 
kinds of timber are simultaneously treated in the creosoting-tank the 
time employed in the process of curing may be amply sutiicient to drive 
out the sap fi'om the pine and thoroughly All its pores with oil, while it 
would not suffice for the hard and close-grained oak, even supposing 
such a result possible of attainment by any reasonable length of curing. 
All of the gun-i)latforms examined were creosoted in 1S71, except four 
fr()nt-i)i idles at JJattery lludson and two front-pintles and one center- 
jjintk' at Vovi I*nlaski, wliicli were cured in 1872. Those at the works on 
ytaten Island, >J. Y., were laid either in 1873 or 1871, tlie four i)lat- 
lornisat l^'orts Monltric and Snmter in 1872, and the tliree Pnhhski phit- 



forms in the spring of 1874. The mortar-platforms were creosoted in 
1872, and laid in May and June, 1873. 

All of these platforms may be regarded as being serviceable at the 
present time, with the exception, i:>erhaps, of the center-i)intle platform 
at Fort Pulaski ; but as it may be presumed that the pieces attacked 
with decay will more or less rapidly waste away and seriously impair 
the strength of the j)latforms, it would be well to remove the defective 
parts as soon as possible and replace them with sound timbers. The 
two front-pintle platforms at Fort Pulaski, but not the center-pintle, had 
received a coat of tar i)reviously to being laid, and their apj)earance 
wh^n inspected seemed to indicate that this operation aided materially 
in preserving at least the pine timbers from decay, by filling up the sun 
cracks and splits. 



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12 

THE BETHELL PROCESS. 

This system has been applied to — 

4 froiit-pintle platforms for lo" gims^ high traverse. 

22 frout-pintle platforms for 15*'^ gnus, low traverse. 

8 platforms for IS" seacoast mortars. 

Of these platforms, two low-traverse gun-platforms and four mortar- 
platforms are stored at Fort Moultrie, S. C, and two low-traverse gun- 
j)latforms at Fort Sumter, S. C. 

The balance have been laid at the following works : 

4 gun-platforms, low traverse, I^orth Olifif Battery, ^. Y. 

7 gun-platforms, low traverse, Fort Moultrie, S. C. 

3 gun-platforms, low traverse, Fort Sumter, S. C. 

4 gun-platforms, low traverse. Fort Pulaski, Ga. 
4 gun-platforms, high traverse, Fort Jackson, Ga. 
4 mortar-platforms, Fort Moultrie, S. C. 

The platforms laid at the North Cliff Battery and at Forts Moultrie 
and Sumter were examined in September, 1878, and those at Forts 
Pulaski and Jackson in the following December. 

Among the platforms inspected there were, therefore, 22 gun-plat- 
forms and 4 mortar-platforms which had been treated by the Bethell 
process. The results are summed up in Table II. 

Of the 22 gun-platforms treated by this process, 15 were found entirely 
sound as to their oak timbers, that is, about 68 per cent, of the whole 
number -, while of 30 front-pintle platforms treated by the Seely process 
only 23 per cent, have their oak x3ortions intact. The other 7 platforms 
of the 22 had each from 1 to 5 pieces badly decayed -, they are those 
located in the two works on the Savannah Eiver. 

Out of sixty large pieces of white oak forming the top layer of the 
four mortar-i^latforms at Fort Moultrie, only three pieces are reported 
as badly decayed, the rest being sound. 

Neither the Bethell nor the Seely process seems to be calculated to 
secure a thorough saturation or penetration of hard oak by the creosote 
fluid. Indeed, such a result is not deemed possible by Mr. John Beth- 
ell himself, as shown by his letter to Messrs. J. G. Moore & Co., dated 
June 11, 1874. 

The oak was probably better seasoned than that treated by the Seely 
process, although it is claimed for the latter that previous air seasoning- 
is not necessary. The gun-platforms, treated hj the Bethell process, 
were made in tlie summer of 1873, and it is possible that on that occa- 
sion a comparatively better stock of oak timber was used than in the 
case of the platforms treated by the Seely process, which were made from 
Kovembei', 1870, to INFjiy, 1871. Tlie mortar-platforms were treated dur- 
ing the winter ol' JS73-'74. 

The yellow-pin(^ timber was found entirely sound in 13 front-pintle 
l)latr<niiis. 1m\(' i)lat forms at Fort IMoultrie have each from one to three 



13 

pieces attainted by decay; while of the four i)hitforms at Fort Jackson 
those parts of the radial timbers that were imbedded in the earth were 
all considerably decayed. The yellow-pine timber forming the bottom 
of the fonr mortar-platforms at Fort Monltrie were fonnd quite sound. 

Considering that all the gun-platforms treated by the Bethell process 
were finished and creosoted during the same season — ^the summer and 
antumn of 1873 — and by the same contractor, it is somewhat remarkable 
that the yellow-pine timber of the Fort Jackson iDlatforms should have 
proved to be in such a poor condition as compared with that of the 
others. They were, however, creosoted a few months before the rest, and 
it may be that they were not so carefully treated as those laid at the 
other works. Perhaps, also, the locality has an unfavorable influence 
on the durability of the timber. Fort Jackson being but little elevated 
above the Savannah Eiver, and surrounded to a great extent by rice- 
plantations and swamp-land. The warm and damiD atmosphere gen- 
erally prevailing there is constantly acting on the timber, and possibly 
promotes decay more quickly and rapidly than at the forts nearer the 
sea shore where the air is cooler and purer from the sea breezes. 

The entirely sound condition of the platforms treated by the Bethell 
process at the North Clifl' Battery, l^ew York Harbor, and of those at 
Fort Sumter, Charleston Harbor, seems to show that location may be 
of considerable im])ortance in regard to the preservation of timber. 
Indeed, the comj)aratively cooler climate to which the first-mentioned 
platforms are exposed might have been expected to favor their preser- 
vation. At Fort Sumter the platforms rest on a terre-plein formed 
entirely of sand, which never retains moisture on its surface for any 
considerable length of time, and being sufficiently elevated for free 
exposure to sun and breezes, the moisture which condenses or settles on 
the timber is generally soon evaporated. 

The Fort Jackson platforms rest upon masonry arches, with but little 
sand intervening. 

All the platforms treated by the Bethell process may be considered 
as serviceable, except those at Fort Jackson, although requiring in 
some cases a removal of a few pieces. 

The results of the inspection do not seem to point out any material or 
noteworthy difference in the efficiency of the two processes^ employed. 
If faithfully applied either of them will greatly prolong the life of plat- 
form timbers. 



14 



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The Hayford process appears to promise better results tlian either,, 
inasmuch as the creosote oil is let into the tanks ux)on the timber, TN'hile 
a more or less perfect vacuum exists there, and, therefore, while the 
pores are open to the reception of the liquid. 

Two of the three platforms laid at Fort Sumter, in Ai)ril, 1874, were 
some time afterward fitted with extra pieces of timber to adapt them to 
receive carriages for 200-pound Parrot guns. These timbers were not 
creosoted, but they received a coating of tar. The inspection made in 
September, 1878, showed every one of them badly decayed, while the 
older creosoted timber had remained perfectly sound. One of the radial 
pieces of pine in one of the Fort Moidtrie platforms had been broken 
during the transportation. One part of it was lost and its place supplied 
by a new piece scarfed on to the old one. This new piece, which was 
not creosoted, is now entirely decayed, while the creosoted remnant of 
the original stick has remained sound. In December, 1871, four wooden 
platforms for 200-pound Parrot rifles, not creosoted, were laid, two at 
Fort Moultrie and two at Fort Sumter. They are now, and have been 
for some time, entirely decayed and unserviceable; audit is reported 
that the guns and carriages mounted on them at Fort Moultrie will soon 
fall unless they are dismounted. 

These different results obtained with raw and creosoted timber, placed, 
as it w^ere, side by side, and subject to exactly the same influences, while 
showing the powerftil preservative properties of the carbolic acid con- 
tained in the creosote of coal tar, also show the necessity of applying 
the curing process very thoroughly in order to secure benefits commen- 
surate with its cost. 

When the contracts were made for treating the platforms mentioned 
in this report, it was stipulated that a certain amount of creosote oil 
should be forced into the pores of the wood. It is impossible, however, 
to ascertain whether the wood has been actually impregnated with any 
stipulated quantity of oil. 

Dependence must be placed upon the honesty of the parties doing the 
work, unless such a system of supervision be adopted as will indicate 
to the inspector the quantity of oil consumed daily. The difference of 
weight of a piece of timber, before and after treatment, will not show 
how much oil has been absorbed by it, since it would also be necessary 
to know how much of its raw weight the timber has lost by the expulsion 
of sap and moisture while in the tank. On one occasion it was found 
that a piece of creosoted platform timber delivered at Staten Island 
directly from the works actually weighed rather less than a block of 
untreated wood cut from the same stick. 

It is claimed tliat the volume of oil forced into the timber is exactly 
measured by the gauge on the oil-reservoir, and that the sap and moist- 
ure evaporated from the Avood and subsecpiently condensed and drawn 
off can also be measured. ]]ut to protect the interests of tlie riiited 
States (loverimieiit it would be necessary to employ an inspector who is- 



17 

conversant with the theory of the process as well as its practical details, 
and who should be in constant attendance at work where govern- 
ment timber is being treated, in order to keep the operations under his 
personal surveillance. 

There seems to be a dearth of trustworthy information with respect 
to the quantity of oil that can be forced into the various kinds of wood 
indigenous to this country. Mr. Bethell says that he can put 10 i30unds 
of creosote oil into a cubic foot of yellow pine, and that he has forced 
as much as 12 pounds into some red fir; but this is rarely done. Into 
timber for ordinary use he puts 8 pounds, and as protection from the 
ship-worm, 10 pounds. He says that he has no experience Avith white 
oak, but has put from 3 to 5 pounds into French oak. Mr. Moir, in a 
paper read before the Philosophical Society of Glasgow, recommends 8 
pounds of oil per cubic foot for land purposes, and 10 to 12 x3ounds for 
marine work. He says that the maximum nsed in France, Belgium, and 
Holland is from 16 to 26 iDounds, and that beech has taken as much as 31 
pounds. 

Professor Blaney, of Chicago, in a letter to Mr. W. T. Pelton on the 
Seely process, says that from examination he found that the weight of 
a prepared block containing 8 cubic inches was 2,456 grains, while a 
similar block of the saiiie wood unprepared weighed only 1,126 grains, 
l)roving apparently that 1,330 grains of the dead oil had been intro- 
duced into the wood. The kind of wood is not stated. It may have 
been sap-wood of a very porous and absorbing species. 

It may be safely assumed that wood — any kind of wood — thoroughly 
imi^regnated with creosote oil, will resist for many years aU ordinary 
causes of decay, and also resist for a number of years the attack of the 
teredo. The teredo will not touch timber containing any considerable 
quantity of creosote. The point ni)on which any doubt hangs is the 
permanency of the impregnation when the wood is immersed in sea- 
water. If the creosote does not become diluted and dissolved out, 
the wood should continue to withstand the ravages of the worm. Com- 
plete impregnation to the limit of saturation being, so far as we know, 
essential to the entire success of all processes of treating timber with 
creosote or carbolic acid, to be used for either land or submarine con- 
strnction, it is imjiortant that the most thorough method of treatment 
should be ascertained in order that it may be encouraged and fostered. 

Yaluable infonnation would be elicited by. a series of experiments 
conducted mth a view of ascertaining the oil-absorbing capacity of the 
most imi^ortant woods nsed for building purx)Oses in this country, and 
the variations of capacity" in the same Avoods when green, rafted, air-sea- 
soned or kiln-dried ; and of heart and sap-wood from the same tree. 

Mr. BetheU thinks that it is impossible to drive the oil into the heart 

of hard wood, but that the sap-wood is impregnated and a water-proof 

envelope formed, rendering the wood imi^ervious to air and moisture. 

It has been observed in England that in creosoted railway-sleepers of 

2 p T 



18 

Scotch fir, such cases of decay as liave occurred were found to have 
taken place in the heart- wood, but ui3on experimenting upon the trans- 
verse strength of a sleeper that had lost a portion of its heart, it was 
found quite as strong as a similar sleeper uncreosoted, because the young 
wood (or sap-wood) had become so hard from thorough impregnation 
that the sleeper resembled an iron pipe. And it was also observed that 
the half-round sleepers lasted longer than the square form, simply be- 
cause they retained all the sap-wood which the other lost in squaring. 

This observation is essentially corroborated by experience had at the 
recent examination of platforms. The sticks of oak timber were in many 
cases hard and sound on the surface, but sounded hollow when struck 
with a hammer 5 because the heart was beginning to, or had already 
advanced in, decay. This condition of the oak does not necessarily prove 
that a renewal of the pieces is indispensable, provided the decaj^ remains 
confined to the heart-wood. For its proper purposes a platform con- 
structed of 12-inch by 12-inch or 12-inch by 16-inch timber may be con- 
sidered as still serviceable, even after the heart, for a thickness of a few 
inches, has become decayed and rotten. 

Whenever practicable the timber should be used in its natural round 
form, with the bark removed, but not hewn, or squared in the mill. The 
sap-wood is undoubtedly that portion of it which can be more thoroughly 
impregnated with the oil than the denser heart- wood, and any cutting 
away of the outer rings will diminish the amount of oil that can be 
forced into the wood. 

In regard to the species of wood to be employed in constructing gun- 
platforms it may in future become a question whether the use of white 
oak is really indispensable, or whether it might not with safety, and 
even with advantage, be replaced by yellow pine. It seems very diffi- 
cult, if not impossible, to impregnate oak as thoroughly as we can pine. 
It is quite certain that it cannot be made to absorb as much oil as the 
latter. It has been claimed by some engineers that creosoting adds 
considerably to both the hardness and the strength of soft woods like 
pine. If this statement can be substantiated by further experiments, it 
will be advisable to replace the oak portions of platforms by well-cured 
yellow pine, this being not only cheaper than oak at first cost, but giving 
greater assurance of durability. 

To show the results of the examination of all platforms treated by 
either the Seely or Betheil process in a condensed form, the following 
tables have been i^repared : 

Table III gives the whole number of pieces treated by the process 
for each kind of wood employed, the number of pieces and their per- 
centage of the whole number found thoroughly sound, and the number 
of pieces and tlieir percentage of the whole that were found attainted 
by decay, either partially or throughout. 



19 



Table III. 







•^ 










1 


Sound. 


Unsound. 




.^ 


■^ 






Process of curing. 


Kind of wood. 


as 




Si's 




o 






-J "■ 


Ms 


P 


Ss 


If 






c 


~ ?H 


gS 


g& 


9 2 












s 














O -t-i 






r- 


^ 


A^ 


^ 












P. cent. 




p. cent. 


Seelv 


Oak 


479 
1, 422 


241 
1, 3.59 


50.3 
9,5.0 


238 
63 


49.7 


1)0 


Yellow pine 


5.0 


Bethell 


Oak 


460 


429 


98.3 


31 


6.7 


Do 




484 


410 


84.7 


74 


15.3 









• Table TV gives the volumes in cubic feet treated hy either process, the 
number of cubic feet and their i3ercentage of the whole considered 
sound, and the number of cubic feet and their percentage of the whole 
actually decayed. 

Table IV. 







i 


Sound. 


Decayed. 




_^ 


'^ 


. 


<« 


Process of curing. 


Kind of wood. 




■SIS 


?A 




o . 
tic 






Mi 

S3 


II 
1 


S3 


u 








! 

1 P. cent. 




p. cent. 


Seelv 


Oak 


3,035 
13, 650 


2,841 
13, 440 


93.6 
98.5 


194 
210 


6.4 


iDo 


Yellow pine 


1.5 


Bethell 


Oak 


3,430 
7,660 


3,248 
7,133 


94.7 
93.1 


182 
572 


5. 3 


Do 


Yellow pine 


6.9 



This table shows as correctly as it is possible, without taking up sin- 
gly eve3?y piece of timber for close examination, the true proportion, by 
volume, of sound and decayed timber. As an illustration of the mode 
by which it was prepared a few instances will be given. A stick of yel- 
low i^ine, 12 inches square and 20 feet long, containing 20 cubic feet, 
was reported to be more or less decayed for, say, two feet of its outer 
end. Therefore, 18 cubic feet were entered as sound and 2 cubic feet as 
decayed. All of the yellow-pine radial timbers of the Fort Jackson plat- 
forms were reported as sound in the upper half of their body and decayed 
in the lower half Therefore, one-half of their cubic contents was 
entered in the table as sound and the other lialf as decayed, and so on. 

It seems proper to remark that the comparative large percentage 
of decayed yellow pine in platforms treated by the Bethell process is 
solely due to the Fort Jackson platforms, which, as already stated, were 
found to be in a rather abnormal condition. 

To sum up, it may be said that the treatment of platform timber by 
either the Seely or Bethell process has thus far answered the purpose, 



20 

and that of the two woods used, j^ellow pine has generally proved supe- 
rior to white oak in resisting decay. 

It is recommended that after the lapse of some years another exami- 
nation of the platforms should be made and the condition of their tim- 
bers ascertained. 

Yery respectfully, your obedient servant, 

Q. A. GiLLMORE, 

Lieut. Col of Engineers J Bvt. Maj. Genl, U. S. A. 
Brig. Gen. A. A. Humphreys, 

Chief of Engineers^ U. 8. A. 



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